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Ask Slashdot: Your Most Unusual Hardware Hack?
An anonymous reader writes: Another Slashdotter recently asked what kind of things someone can power with an external USB battery. I have a followup along those lines: what kind of modifications have you made to your gadgets to do things that they were never meant to do? Consider old routers, cell phones, monitors, etc. that have absolutely no use or value anymore in their intended form. What can you do with them?
Put it all together for near-real-time track of how much it costs to keep my basement at a given humidity.
The Raspberry Pi caches readings in a local database in case it can't connect to the web, then stores in a database on my web server. The database ingestion also keeps a 2-hour running average to smooth things out a bit.
When I set it up, I thought it wasn't working right - I saw sawtooth-like patterns in the humidity data. Turned out, it was working perfectly: the resolution of the humidity sensor was good enough that I could watch the humidity in the room rise until the dehumidifier kicked on!
A company I worked at used to have an annual mini golf hole contest. I hollowed out a computer and ran the ball through it in some 1/2 pvc pipes with the cd tray popping in and out (a batch file from a boot floppy) as a moving obstacle.
The HP28C had an infrared output, e.g. For printers, but no input. a friend of mine published a book explaining how to connect an IR diode to trigger some unconnected keyboard lines in the calculator. That made it possible to upload programs to the calculator faster. Of course you also needed the matching hack on a PC to send programs. The 48 had IR in both directions.
-- Did you try Tao3D? http://tao3d.sourceforge.net
Back in the early 90s my dad repurposed an old Tandy laptop to effectively act as a scheduled wall timer for a "VCR for tape decks". He used the parallel port to send current to a few signaling contacts on a cassette recorder in order to record Car Talk and a few other radio programs he liked. A patent was considered, but podcasts rapidly became a thing a year or two after he had it working nicely. Not a bit of that statement that fails to make me feel a bit old.
Beautiful. I too was deployed to Iraq. Some Major got bit by the Good Idea Fairy and wrote an Access Database to store all of our flight data. It took him half the deployment to write that. Meanwhile, we were storing all the data in Excel. Once it was ready, he wanted us to import the data to his Access DB. And of course, it wouldn't just import because the table structures were too different. So we were to import all 15k records by hand. As you know, military PCs are all locked down, but AutoHotKey has a scripting language and does not require admin privileges to run, so I spent a week writing a script that alt-tabbed between the Excel sheet and the Access DB and copied and pasted each cell into each form field until the damn thing was imported. Not a hardware hack, per se, but definitely a hack. Got an ARCOM out of that for saving everyone a shitload of time and their sanity.
At one time I got a broken MagSafe power supply, the ones that Apple ships with their laptops. Since I was curious how these switched-mode power supplies work, I cracked it open and somehow shorted the big capacitor. These temporarily store up to 400 volts but it wasn't that much left. I still got quite a zap, though :-)
Anyway, I got a big crate of broken ones from a local Apple dealer in town. I found out that they usually didn't work because the wire would break close to the adapter. eBay sold replacement cables and I started fixing the power supplies. Cracking them open, replacing the cord, testing them, glueing them shut as neat as possible, then selling them for 25 bucks.
It was fun but with a kid on the way, I had no room for a separate table for my soldering iron, electronics stuff etc. and I stopped doing it. Cleaning up every time you want to do something small isn't fun.
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Old HP GPIB-based XY plotter with laser diode in place of pen, does a nice job of cutting gaskets for steam engines.
Broken 8 track player in ginormous am/fm/turntable cabinet, replaced with beaglebone, so when I hit the next track button it plays a 'clunk' sound and then fires up a random streaming internet radio station. (That one made hackaday.)
A nearby company went out of business and sold all their stuff and I scored an electronic balance with an RS232 output. Some arduino code later, and I now have a fuel injector flow tester: force known-pressure fuel in for a known amount of time and measure how much actually comes out, tare, repeat. It's neat to be able to characterize just how narrow a PWM signal the injector can register and react to.
My current work project is even a hack: I'm repurposing an abandoned semiconductor automated test system into an evaluation board characterization system. The test guys don't want it because it's too slow and limited, but I'm all "whoah, 192 arbitrary waveform generators? Let me at it."
Nostalgia's not what it used to be.
Oh, god, space technology is full of brilliant hacks. For example, New Horizons' radio. It has two amps connected to one dish, designed as a primary and a backup. But while it was en route, an engineer hit upon an idea to have them both transmit at the same time through the same dish, doubling the bandwidth. Normally that wouldn't make sense, except that the amplifiers have signals with different polarization, and these can be separated back out on Earth.
Great, except for one problem. The second radio was designed as a backup, they weren't planned for simultaneous operation - so there's not enough power to run them both and everything else at the same time. There's barely enough power to run just the radios - and I mean, it's not like you can just shut off the flight computer to free up more power. Well... actually, that's exactly what they do. When have a ton of data accumulated that they want to get to Earth and no critical science to do, they spin the craft up like a bullet to keep it stable and the dish pointing at Earth. Then they shut down the whole guidance and control system and pretty much everything else on the craft not essential for reading and transmitting data. It stays in this mode for days for a week or two, until all of the onboard data is transmitted, then they spin it back down so that they can do things like take pictures once again.
"Who the **** put an emergency exit in the interrogation room?!" -- Police chief, "Jesus Christ Supercop"